Peroxygen bleaches have long been known to be effective in removing stains and/or soils from textiles and the like. Detergent compositions containing an oxygen-releasing compound, for example an inorganic persalt, such as an alkali metal perborate or percarbonate or peroxides such as urea peroxide have been disclosed as useful for bleaching and sanitizing purposes. Such bleaches, however, are highly dependent on temperature for efficiency. For example, temperatures in the range of about 95.degree. C. to about 100.degree. C. are satisfactory for such bleaches while temperatures lower than about 75.degree. C. have been shown to decrease the efficiency of the bleach to an unsatisfactory level.
In recent times textiles have been made which are best laundered in low temperature wash water. Such temperatures are in the range of unsatisfactory performance for the above-mentioned bleaches. Further, concern for energy conservation has created a need for laundry detergents, and other materials such as bleaches, such that all textiles can be laundered at lower temperatures at which previously known bleaches are unsatisfactory.
Previous attempts to overcome the disadvantages noted above have resulted in various teachings and prior patents relating to detergent formulations containing oxygen-releasing compounds such as persalts and peroxides with the goal of providing more effective bleaching and sanitizing activity in temperatures as low as 50.degree. C., usually between 50.degree. C. and about 75.degree. C. Typical examples of such attempts are described in U.S. Pat. No. 3,256,198 to Matzner issued Jun. 14, 1966. Matzner discloses generically alkyl and aryl carbonates wherein the aryl may be substituted, for example, by halo, nitro and sulfo groups. The alkyl groups or radicals may contain from about 1 to 20 carbon atoms. However, only dialkyl or diaryl symmetrical carbonates in a limited class of compounds are demonstrated as being useful.
In another attempt to solve the problem of bleaching efficiency in relatively low temperature laundering processes, sodium p-sulfophenyl alkyl carbonates were disclosed to be useful in U.S. Pat. No. 3,272,750 to Chase, issued Sep. 13, 1966. However, the relatively low molecular weight alkyl and phenyl carbonates disclosed therein do not demonstrate bleaching efficiency adequate for present needs.
Since the need for energy conservation has become more acute in recent years, there have been more recent attempts to increase the efficiency of bleaches in low temperature wash water. In most instances, a peroxide-ester bleaching composition has been taught to be useful and as having higher efficiency than the previous combination of low molecular weight carbonates with persalts. Examples of this art are found in U.S. Pat. No. 4,539,130 to Thompson, et al. Acyloxybenzene sulfonates are disclosed as efficient peroxygen bleach activator compounds useful in detergent compositions at relatively low wash water temperatures. A review of the prior art of bleach activator compounds is disclosed in this patent which is hereby incorporated by reference. Other examples of recent attempts to establish greater efficiency in bleach activator compounds useful in laundering at relatively low temperatures are represented by European Patent application 0 147 191 to Hegemann et al published Jul. 3, 1985, and European Patent application 0 098 108 to Garner-Gray published Jan. 11, 1984. These European patent applications contain a large list of peroxygen bleach activator compounds including a few carbonates in common with the U.S. patents to Matzner and Chase referred to above.